Longitudinal logistic regression with continuous-time first-order autocorrelation structure
Hi Dennis, Another way to go would be to include a random intercept and a random time effect (both over persons) in the logit, much like is done in linear models. This creates correlation between logit values across successive time-points. This is e.g. explained in Snijders and Bosker's book and in Singer and Willett. You can make the model increasingly more flexible (in terms of the correlation structure over time) by not only including a linear random time effect but also a quadratic, cubic etc. time-effect. This is a different approach than letting the error terms "e" correlate over time. But it serves the same end: correlation over time. I think there's nothing wrong with this "multilevel growth model" approach for a glm, but anyone please correct me if I'm wrong. Anyway, it can be carried with most multilevel or random effects software packages, like glmer in R. Best regards, Ben.
On 27/02/2018 07:22, Dennis Ruenger wrote:
Dear All. I need to analyze an intensive longitudinal data set with a binary outcome variable. In the ?Ecological Momentary Assessment? (EMA) study, participants received five random prompts per day for six weeks, asking them (among other things) whether they were craving a particular drug (yes/no). At the most basic level, I want to know whether the likelihood of craving the drug changed across time. Given the variable time intervals of measurement and many missing data points, a continuous-time first-order autocorrelation model seems necessary. I found tutorials on how to allow for continuous-time autocorrelation and missing data in an LMM, using nlme::lme and corCAR1, but I am at a loss as to what to do in a GLMM. I would be thankful for any suggestions on how to analyze this kind of data in R. Dennis [[alternative HTML version deleted]]
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